What to Know About Horse Hoof Abscesses and Gravel

Even the tiniest of cracks can let bacteria in. And yes, the white line is not white.

What is a Hoof Abscess in Horses?

• Simply put, a hoof abscess is a pocket of infection in the foot. Somehow, bacteria have entered the deeper structures of the hoof, started multiplying, and caused an infection.

• Other infections, like white line disease, are similar in that they harbor bacteria and sometimes fungus. White line infections creep their way up small hoof cracks and into the layers of the hoof wall.

• In contrast, an abscess inside the hoof capsule involves pus, bacteria, and sometimes fungus. And while white line is usually not painful, abscesses certainly are.

The role of white blood cells

• White blood cells are part of the body’s cleansing of foreign invaders. As infections progress and the bacteria multiply, so do the white blood cells and other inflammatory factors the immune system makes.

• This mix of dead cells, foreign bacteria, and associated inflammation from the immune response creates pockets of pus. This pocket of pus may look like a pimple or soft swelling that can be popped or drained. But the hoof capsule’s rigid structure prevents this, and the pressure build-up causes incredible and quickly developing severe pain in the affected foot.

These thick leather boots are great for abscesses and trail riding but maybe not simultaneously.

How Do Bacteria Get Into the Hoof?

• There are many ways infectious microbes end up in the hoof. Some are accidental, others are related to poor hoof care.

• Cracks are the most common entry point. These may be from a knock, trauma, or cracks along the hoof wall resulting from the wet or dry cycle that change the hoof enough to create an opening.

• Hoof bruises can turn into an abscess. You will likely see lameness from the bruising. Know it can morph into other hoof problems.

• A horse with laminitis is also more likely to suffer from abscesses due to the damaged structures in the hoof. Recurrent abscesses are likely in horses with chronic laminitis as the laminae have less blood flow and are misshaped.

• Horses with pituitary pars intermedia dysfunction (PPID, formerly known as Cushing’s disease) and other metabolic disorders like equine metabolic syndrome (EMS) are susceptible to abscesses.

Read more about PPID and EMS here. 

These temporary bandages are also great for abscesses, but not trail riding.

Gravel in Horses – A Different Kind of Hoof Infection

• Even the tiniest of cracks can let bacteria in. But, some cracks let the abscess OUT.

• Gravel in horses is an abscess that pops through the coronary band at the top of the hoof.

• Since abscesses can’t pop through the hard horn of the hoof wall, and for the most part, the frog and sole stay intact, abscesses may decide to head up and out in the path of least resistance.

• Gravel in horses is usually associated with a piece of gravel, sand, or dirt that enters the white line and moves upward.

Signs of hoof abscesses

• An abscess usually shows up as sudden and severe lameness.

• Your horse usually has an increased digital pulse in the affected limb(s).

• Know that signs of hoof infections present like laminitis, bruising, puncture wounds, foreign bodies, a street nail, or a hot nail from shoeing.

• The best thing you can do is call your veterinarian. Vets can diagnose, treat, and medicate.

• Many farriers are skilled at digging abscesses out, but a vet can also do this, give your horse pain meds, prescribe antibiotics if necessary, and rule out other problems that may accompany an abscess.

Possible complications in the hoof and leg

• Aside from the pain factor, an abscess can create many other hoof problems.

Coffin bone infections

• An abscess, usually one that returns or never fully heals, may create septic pedal osteitis when the bone itself is infected.

Bone death

• When blood flow is severely compromised, part of the pedal bone may die and fall away from the healthy bone.

Leg swelling

• Cellulitis and lymphangitis may travel up the leg. Both conditions create painful swelling of the lower limb and require immediate attention to prevent further spread up the leg.

Hoof growth deformities

• Severe or chronic abscesses may change how the hoof grows, especially if the area around the coronary band is involved. The coronet creates the hoof wall, and damage there can impact hoof growth.

Treatment and Prognosis

• The prognosis for recovery is good with an abscess, and even better when your vet and farrier can address the issue immediately.

There are lots of hoof goops to choose from. The lovely smelling ichthammol is just one of them!

Work with your veterinarian and farrier for drainage

• You often hear that soaking the hoof in warm water and Epsom salts will pull an abscess out. This process doesn’t always happen! Sometimes, the water and salts dehydrate the sole and frog, making everything harder.

• Ideally, your vet can take X-rays to pinpoint the location and severity of the abscess. Radiographs also let your farrier know if there are affected structures that benefit from a special trim or horseshoe.

• Now, your vet and farrier can create a tract or opening that allows the abscess to drain. Your horse’s weight and gravity will help things drain.

• After creating a track, using a soak, hoof poultice, or packing is infinitely more effective.

Keep the hoof clean and wrapped

• Now that your horse is on the mend, you must keep the hoof safe from further infection.

• You can do many things for wrapping – diapers, duct tape, vet wrapping, etc. I prefer to use an actual boot to hold a diaper in.

• Boots also give you the advantage of keeping the hoof wall edges safe if a shoe has been removed.

• There are many varieties of hoof boots to choose from. Some are great for soaking, others for traction, and some for holding packing or a diaper.

You usually should not wrap over the coronary band, but in some cases, your vet may suggest it, especially if the abscess was a gravel.

What happens if you don’t treat an abscess?

If you don’t treat hoof abscesses, the condition can worsen. The infection may spread to the bone and up the leg, creating even more pain. Immediate care helps prevent serious complications and provides instant pain relief.

If abscesses tend to be common for your horse, time to evaluate your hoof care routine, the balance of his hooves, his diet, and even the footing he lives and works on. You may not be able to do much about the footing, but you could add shoes and/or pads.

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